Security + Cryptography
CRYPTOGRAPHY
Questions and Answers
- 1.
Which of the following is not one of the three main categories of cryptography?
- A.
Steganography
- B.
Physical
- C.
Mathematical
- D.
Quantum
Correct Answer
A. SteganographyExplanation
The three main categories of cryptography are physical, mathematical, and quantum. Steganography is a form of physical cryptography but not a category of its own.Rate this question:
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- 2.
Which type of cipher is a simple coding system that changes one character or symbol into another?
- A.
Reverseography
- B.
Steganography
- C.
Transposition
- D.
Substitution
Correct Answer
D. SubstitutionExplanation
A substitution cipher is a simple coding system that changes one character or symbol into another. There is no such valid cipher as reverseography. Steganography is the hiding of one message within another. A transposition cipher is one in which characters are scrambled in a certain manner.Rate this question:
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- 3.
Which of the following is a hexadecimal value that is computed to verify authenticity?
- A.
Mince
- B.
Checksum
- C.
Denomination
- D.
Integer
Correct Answer
B. ChecksumExplanation
A checksum is a hexadecimal value that is computed to verify authenticity. The other values are not hexadecimal values computed to verify authenticity.Rate this question:
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- 4.
If security is a real concern on your network, what length do most experts recommend as the minimum for password length?
- A.
10
- B.
9
- C.
8
- D.
6
Correct Answer
A. 10Explanation
If security is a real concern on your network, most experts recommend 10 characters as the minimum for password length. They also recommend including as many different character sets as possible.Rate this question:
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- 5.
Which of the following involves looking at blocks of an encrypted message to determine whether any common patterns exist?
- A.
Quantum cryptography
- B.
Algorithm errors
- C.
Frequency analysis
- D.
Brute-force attacks
Correct Answer
C. Frequency analysisExplanation
Frequency analysis involves looking at blocks of an encrypted message to determine whether any common patterns exist. Quantum cryptography is a form of encryption that is based on the characteristics of the smallest particles known. Algorithm errors occur when predictable results create a weakness in the coding system. Brute-force attacks apply every possible combination of characters until a match is found.Rate this question:
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- 6.
Which of the following is the process of converting a message into a numeric value?
- A.
Hashing
- B.
Digitizing
- C.
Conversion
- D.
Reassignment
Correct Answer
A. HashingExplanation
Hashing is the process of converting a message into a numeric value.Rate this question:
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- 7.
Which of the following is not one of the three most common versions of Message Digest Algorithm (MDA)?
- A.
MD2
- B.
MD3
- C.
MD4
- D.
MD5
Correct Answer
B. MD3Explanation
The three most common versions of MDA are MD2, MD4, and MD5.Rate this question:
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- 8.
Which of the following is an update to Secure Hash Algorithm (SHA)?
- A.
SHA-1
- B.
SHA2
- C.
SHB
- D.
SHAA
Correct Answer
A. SHA-1Explanation
The update for SHA is the SHA-1 standard.Rate this question:
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- 9.
What bit hash value does Secure Hash Algorithm (SHA) produce?
- A.
96
- B.
128
- C.
160
- D.
256
Correct Answer
C. 160Explanation
Secure Hash Algorithm (SHA) produces a 160-bit hash value.Rate this question:
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- 10.
What bit hash value does MD5 produce?
- A.
96
- B.
128
- C.
160
- D.
256
Correct Answer
B. 128Explanation
MD5 produces a 128-bit hash value.Rate this question:
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- 11.
Symmetric algorithm encryption methods use either of which two ciphers? (Choose two.)
- A.
Block
- B.
Stream
- C.
Character
- D.
Bit
Correct Answer(s)
A. Block
B. StreamExplanation
Symmetric algorithm encryption methods use either a block cipher or a stream cipher.Rate this question:
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- 12.
Which type of cipher involves the hiding of one message within another?
- A.
Reverseography
- B.
Steganography
- C.
Transposition
- D.
Substitution
Correct Answer
B. SteganographyExplanation
Steganography is the hiding of one message within another. There is no such valid cipher as reverseography. A transposition cipher is one in which characters are scrambled in a certain manner. A substitution cipher is a simple coding system that changes one character or symbol into another.Rate this question:
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- 13.
Which of the following was developed by a Swiss consortium and uses a 128-bit algorithm key for symmetric encryption?
- A.
IDEA
- B.
CAST
- C.
Blowfish
- D.
RC5
Correct Answer
A. IDEAExplanation
IDEA was developed by a Swiss consortium and uses a 128-bit algorithm key for symmetric encryption. CAST was developed by Carlisle Adams and Stafford Tavares and uses a 40-bit to 128-bit key. Blowfish is a 64-bit block cipher. RC5 uses a key size up to 2,048 bits.Rate this question:
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- 14.
Which of the following is an asymmetric algorithm based on calculating logarithms?
- A.
ECC
- B.
Diffie-Hellman
- C.
El Gamal
- D.
Both B & C
Correct Answer
D. Both B & CExplanation
Both Diffie-Hellman and El Gamal are asymmetric algorithms based on calculating logarithms. Here's a brief explanation of each:
Diffie-Hellman: This algorithm is a method for securely exchanging cryptographic keys over a public channel, allowing two parties to establish a shared secret key. It is based on the difficulty of calculating discrete logarithms.
El Gamal: This algorithm is used for public key encryption and digital signatures. It is based on the difficulty of solving the discrete logarithm problem and is an extension of the Diffie-Hellman key exchange.
RSA, while also an asymmetric algorithm, relies on the difficulty of factoring large prime numbers, not logarithms. ECC (Elliptic Curve Cryptography) is another asymmetric algorithm that is based on the algebraic structure of elliptic curves over finite fields.Rate this question:
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- 15.
Which of the following is derived from the message and a key and is used to verify the integrity of a message?
- A.
MAC
- B.
BDC
- C.
ERC
- D.
CDC
Correct Answer
A. MACExplanation
Message Authentication Code (MAC) is derived from the message and a key and is used to verify integrity of a message. The other choices listed are not valid options.Rate this question:
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- 16.
Which of the following is not a key component of PKI?
- A.
CA
- B.
LRB
- C.
RSA
- D.
RA
Correct Answer
B. LRBExplanation
The four key components of Public Key Infrastructure (PKI) are certificate authority (CA), registration authority (RA), RSA, and digital certificates.Rate this question:
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- 17.
Which is named after the creators and uses a 40-bit to 128-bit key for symmetric encryption?
- A.
IDEA
- B.
CAST
- C.
Blowfish
- D.
RC5
Correct Answer
B. CASTExplanation
CAST was developed by Carlisle Adams and Stafford Tavares and uses a 40-bit to 128-bit key. IDEA was developed by a Swiss consortium and uses a 128-bit algorithm key. Blowfish is a 64-bit block cipher. RC5 uses a key size up to 2,048 bits for symmetric encryption.Rate this question:
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- 18.
Which of the following is a form of encryption based on the characteristics of the smallest particles known?
- A.
Quantum cryptography
- B.
Algorithm errors
- C.
Frequency analysis
- D.
Brute-force attacks
Correct Answer
A. Quantum cryptographyExplanation
Quantum cryptography is a form of encryption that is based on the characteristics of the smallest particles known. Algorithm errors occur when predictable results create a weakness in the coding system. Frequency analysis involves looking at blocks of an encrypted message to determine whether any common patterns exist. Brute-force attacks apply every possible combination of characters until a match is found.Rate this question:
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- 19.
What is the primary difference between an RA and LRA?
- A.
The LRA saves the CA from responding to so much traffic.
- B.
The LRA can route requests to more than one CA.
- C.
The LRA can be used to identify or establish the identity of an individual.
- D.
The LRA is available only on the LAN, while the CA is available on the WAN.
Correct Answer
C. The LRA can be used to identify or establish the identity of an individual.Explanation
The Local Registration Authority (LRA) can be used to identify or establish the identity of an individual.Rate this question:
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- 20.
What is the most popular version of X.509?
- A.
Version 5
- B.
Version 3
- C.
Version 2
- D.
Version 1
Correct Answer
B. Version 3Explanation
The most popular version of X.509 is version 3.Rate this question:
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- 21.
Which of the following is a statement that the CA uses to issue certificates and implement the policies of the CA?
- A.
CTP
- B.
CRL
- C.
CPS
- D.
CNS
Correct Answer
C. CPSExplanation
The Certificate Practice Statement (CPS) is a statement that the CA uses to issue certificates and implement the policies of the CA. The Certificate Revocation List (CRL) is a list of the certificates that are being revoked (usually because they were lost or stolen). The other choices are not valid for PKI.Rate this question:
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- 22.
Which of the following is not one of the main types of trust models used with PKI?
- A.
Hierarchical
- B.
Bridge
- C.
Mesh
- D.
Star
Correct Answer
D. StarExplanation
The four main types of trust models used with PKI are hierarchical, bridge, mesh, and hybrid.Rate this question:
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- 23.
Which of the following is based on the idea of using large integer numbers for the basis of asymmetric encryption?
- A.
ECC
- B.
Diffie-Hellman
- C.
El Gamal
- D.
RSA
Correct Answer
D. RSAExplanation
RSA uses large integer numbers for the basis of its process. ECC is based on the idea of using points on a curve to define the public/private key pair. Diffie-Hellman is used for the transmission of keys only. El Gamal is an asymmetric algorithm based on calculating logarithms.Rate this question:
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- 24.
Which of the following is a 64-bit block cipher?
- A.
IDEA
- B.
CAST
- C.
Blowfish
- D.
RC5
Correct Answer
C. BlowfishExplanation
Blowfish is a 64-bit block cipher. IDEA was developed by a Swiss consortium and uses a 128-bit algorithm key. CAST was developed by Carlisle Adams and Stafford Tavares and uses a 40-bit to 128-bit key. RC5 uses a key size up to 2,048 bits for symmetric encryption.Rate this question:
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- 25.
In which PKI trust model does a root CA at the top provide all the information to intermediate CAs?
- A.
Hierarchical
- B.
Bridge
- C.
Mesh
- D.
Hybrid
Correct Answer
A. HierarchicalExplanation
In the hierarchical model, a root CA at the top provides all the information to intermediate CAs (and they pass it down to leaf CAs). This does not happen in the other models.Rate this question:
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- 26.
Which of the following occur when predictable results create a weakness in the coding system?
- A.
Quantum cryptography
- B.
Algorithm errors
- C.
Frequency analysis
- D.
Brute-force attacks
Correct Answer
B. Algorithm errorsExplanation
Algorithm errors occur when predictable results create a weakness in the coding system. Quantum cryptography is a form of encryption that is based on the characteristics of the smallest particles known. Frequency analysis involves looking at blocks of an encrypted message to determine whether any common patterns exist. Brute-force attacks apply every possible combination of characters until a match is found.Rate this question:
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- 27.
Which government agency was formerly known as the National Bureau of Standards?
- A.
NSA
- B.
NIST
- C.
CSS
- D.
IETF
Correct Answer
B. NISTExplanation
The National Institute of Standards and Technology (NIST) was formerly known as the National Bureau of Standards (NBS).Rate this question:
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- 28.
Which is the simplest type of PKI trust model in which a peer-to-peer relationship exists between the root CAs?
- A.
Hierarchical
- B.
Bridge
- C.
Mesh
- D.
Hybrid
Correct Answer
B. BridgeExplanation
In a bridge trust model, a peer-to-peer relationship exists between the root CAs. This can also be true in the mesh and hybrid models, but they are not the simplest model in which this happens. In the hierarchical model, a root CA at the top provides all the information to intermediate CAs (and they pass it down to leaf CAs).Rate this question:
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- 29.
Which of the following is a list of which certificates are being revoked?
- A.
CTP
- B.
CRL
- C.
CPS
- D.
CNS
Correct Answer
B. CRLExplanation
The Certificate Revocation List (CRL) is a list of the certificates that are being revoked (usually because they are lost or stolen). The Certificate Practice Statement (CPS) is a statement that that CA uses to issue certificates and implement the policies of the CA. The other choices are not valid for PKI.Rate this question:
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- 30.
Which of the following is based on the idea of using points on a curve to define the public/private key pair?
- A.
ECC
- B.
Diffie-Hellman
- C.
El Gamal
- D.
RSA
Correct Answer
A. ECCExplanation
ECC is based on the idea of using points on a curve to define the public/private key pair. Diffie-Hellman is used for the transmission of keys only. El Gamal is an asymmetric algorithm based on calculating logarithms. RSA uses large integer numbers for the basis of its process.Rate this question:
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Current Version
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Apr 09, 2024Quiz Edited by
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Dec 31, 2010Quiz Created by
Joelcg
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